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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            width: 400px;
            height: 400px;
            border: solid;
            background-image: radial-gradient(red, yellow, green);
            background-image: radial-gradient(#e66465, #9198e5);
            background: radial-gradient(closest-side, #3f87a6, #ebf8e1, #f69d3c);
            background: radial-gradient(circle at 100%, #333, #333 50%, #eee 75%, #333 75%);
            background: radial-gradient(ellipse at top, #e66465, transparent),
                        radial-gradient(ellipse at bottom, #4d9f0c, transparent);
        }
    </style>
</head>
<body>
    <div></div>
</body>
</html>